drm/nv50: rework PGPIO IRQ handling and hotplug detection

Allows callers to install their own handlers for when a GPIO line
changes state (such as for hotplug detect).

This also fixes a bug where we weren't acknowledging the GPIO IRQ
until after the bottom half had run, causing a severe IRQ storm
in some cases.

Reviewed-by: Francisco Jerez <currojerez@riseup.net>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

1 files changed, 3 insertions, 3 deletions

diff --git a/drivers/gpu/drm/nouveau/nouveau_dp.c b/drivers/gpu/drm/nouveau/nouveau_dp.c
index 4562f309ae3d..38d599554bce 100644
--- a/drivers/gpu/drm/nouveau/nouveau_dp.c
+++ b/drivers/gpu/drm/nouveau/nouveau_dp.c
@@ -279,7 +279,7 @@ nouveau_dp_link_train(struct drm_encoder *encoder)
         struct bit_displayport_encoder_table *dpe;
         int dpe_headerlen;
         uint8_t config[4], status[3];
-        bool cr_done, cr_max_vs, eq_done;
+        bool cr_done, cr_max_vs, eq_done, hpd_state;
         int ret = 0, i, tries, voltage;
 
         NV_DEBUG_KMS(dev, "link training!!\n");
@@ -297,7 +297,7 @@ nouveau_dp_link_train(struct drm_encoder *encoder)
         /* disable hotplug detect, this flips around on some panels during
          * link training.
          */
-        pgpio->irq_enable(dev, nv_connector->dcb->gpio_tag, false);
+        hpd_state = pgpio->irq_enable(dev, nv_connector->dcb->gpio_tag, false);
 
         if (dpe->script0) {
                 NV_DEBUG_KMS(dev, "SOR-%d: running DP script 0\n", nv_encoder->or);
@@ -439,7 +439,7 @@ stop:
         }
 
         /* re-enable hotplug detect */
-        pgpio->irq_enable(dev, nv_connector->dcb->gpio_tag, true);
+        pgpio->irq_enable(dev, nv_connector->dcb->gpio_tag, hpd_state);
 
         return eq_done;
 }